The flag makes 'sort' command ignore non-dictionary symbols
(non-alphanumeric and non-spaces). The only difference with GNU sort is
that it takes ALL alphanumeric symbols, not only ASCII ones.
.# Discussion
This commit adds support for a '-f'/'--file' option which reads "KEY=VALUE" lines from
a config (or ini) style text file and sets the corresponding environment key. This is
modeled after the same option in the `dotenv` and `godotenv` commands. Notably, this
commit does *not* add automatic loading of ".env" configuration files.
The environment variables set by reading the configuration file are set prior to any
unset (eg, `-u BAR`) or set (eg, `FOO=bar`) actions. Files are loaded in order with
later files overwriting any overlapping environment variables, then, unset actions (in
command line order) are executed, then, finally, set actions (in command line order)
are executed.
[1] [`dotenv`](https://github.com/bkeepers/dotenv)
[2] [`godotenv`](https://github.com/joho/godotenv)
There was an issue with autoformat when the files had a different
number of columns in the first line. This commit fixes the issue and
extends the related test to cover this case.
Make at_line_start persist between printing each file. This fixes an
issue when numbering lines in the output and one of the input files
does not have a trailing newline.
FileMerger receives Lines Iterables of the pre-sorted input files
via push_file() It implements Iterator, which yields lines from the
input files in (merged) sorted order. If the input files are not sorted,
then the behavior is undefined.
Internally, FileMerger uses a
std::collections::BinaryHeap<MergeableFile>.
MergeableFile is an internal helper that implements Ord in a way that
BinaryHeap can use (note that we want smallest-first, but BinaryHeap
returns largest first, so MergeableFile::cmp() calls reverse() on
whatever compare_by() returns.
Made a new function sort_by(lines, compare_fns), which accepts a
list of compare_fns and calls lines.sort_by() with a closure that
calls each compare_fn in turn until one returns something other
than equal.
Default behavior ensures that String::cmp is the last element in the
compare_fns list (referred to as 'last resort' sorting by man sort).
Passing --stable (-s) turns this behaviour off.
Test cases provided for `sort --month` and `sort --month --stable`.
Instead of using numerals to denote individual cases, I used descriptive
case names. I also changed the extension for the expected output fixture
to match other tests.
I removed one redundant test and another unnecessary helper function.
The repetition of "foo" and "bar" made for difficult-to-read assertion failures
when hacking on `tail`. I think that having each line have unique contents makes
it a bit easier to parse.
